Leaf Spring Track Latch

ABSTRACT

A seat track assembly is provided for mounting a seat to a vehicle floor A fixed track is mounted to the floor and a movable track is fixedly secured to the seat and slidably coupled to the fixed track. A latch is operatively coupled to the movable track for selectively engaging the fixed track. A towel bar is operatively coupled to the latch for actuating the latch between a locked position coupled with the fixed track to prevent sliding movement between the fixed and movable tracks and an unlocked position decoupled from the fixed track to allow sliding movement between the fixed and movable tracks. A leaf spring extending between the movable track and the latch biases the latch into the locked position and permits resilient movement of the latch along a linear path between the locked and unlocked positions in response to pivotal movement of the towel bar.

FIELD OF THE INVENTION

The invention relates to a seat track assembly for a motor vehicle seat. More particularly, this invention relates to a seat track assembly including a leaf spring for biasing a latch to a locked position and permitting resilient movement of the latch along a linear path between the locked position and an unlocked position.

BACKGROUND OF THE INVENTION

Automotive vehicles include seats for supporting occupants within the vehicle. Seats typically include a seat track assembly interconnecting the seat to a vehicle structure, such as a floor, to allow selective locking and fore and aft adjustment of the seat along the floor among a plurality of seating positions. The seat track assembly typically includes a fixed track that is fixedly secured to the floor of the vehicle and a movable track that is fixedly secured to a bottom of the seat and slidably coupled to the fixed track.

Often, a manual seat adjuster is provided to actuate the seat track assembly to control the fore and aft adjustment of the seat. Typically, the manual seat adjuster may be a towel bar or other handle which actuates a latching mechanism. The latching mechanism selectively secures the movable track relative to the fixed track, thus preventing further fore and aft adjustment of the seat. Such latching mechanisms typically will include a latch with windows operatively coupled to one track which engage teeth on the other track, or a latch with at least one tooth operatively coupled to one track which engages an opening or notch in the other track. The towel bar typically has a handle portion which is located at a front of the seat, directly below a seat cushion. The towel bar is used to actuate the latching mechanism between a locked position and an unlocked position.

The latching mechanism is ordinarily in the locked position preventing the seat from moving fore and aft relative to the vehicle. When a seat occupant desires to adjust the seat fore or aft, the towel bar is pulled upward and the latching mechanism moves to the unlocked position, thereby permitting fore and aft adjustment of the seat. Once the seat occupant adjusts the seat to the desired position and releases the towel bar, the latching mechanism automatically returns to the locked position, thereby preventing further fore and aft adjustment of the seat.

While such latching mechanisms are common in the vehicle seating art, current designs use numerous parts, which is not conducive to low cost or rapid assembly of the seat track assemblies. It therefore remains desirable to provide a simple and robust latching mechanism having a minimum number of parts, a low cost to produce, and which can be rapidly assembled.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a seat track assembly is provided for mounting a seat to a vehicle floor. The seat track assembly includes a track mechanism having a fixed track that is adapted to be mounted to the vehicle floor and a movable track that is adapted to be fixedly secured to the seat and slidably coupled to the fixed track. The seat track assembly also includes a latch that is operatively coupled to the movable track for selectively engaging the fixed track to interlock the movable track relative to the fixed track. The seat track assembly further includes a towel bar that is operatively coupled to the latch for actuating the latch between a locked position coupled with the fixed track to prevent sliding movement between the fixed and movable tracks and an unlocked position decoupled from the fixed track to allow sliding movement between the fixed and movable tracks. In addition, the seat tack assembly includes a leaf spring that extends between the movable track and the latch. The leaf spring biases the latch into the locked position and permits resilient movement of the latch along a linear path between the locked and unlocked positions in response to pivotal movement of the towel bar.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a seat track assembly including a towel bar and a pair of latching mechanisms according to the invention;

FIG. 2A is a fragmentary, cross-sectional side view of the seat track assembly with the towel bar lifted and a latch in an unlocked position;

FIG. 2B is a fragmentary, cross-sectional side view of the seat track assembly with the towel bar in a use position and the latch in a locked position;

FIG. 2C is a fragmentary, cross-sectional side view of the seat track assembly with the towel bar forced downward and the latch in the locked position;

FIG. 3 is a fragmentary, partially cut-away perspective view of a track mechanism illustrating the latch in the locked position;

FIG. 4 is a fragmentary, partially cut-away perspective view of the track mechanism illustrating the latch in the unlocked position;

FIG. 5 is a cross-sectional view taken along lines 5-5 of FIG. 3; and

FIG. 6 is a cross-sectional view taken along lines 6-6 of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the Figures, FIG. 1 discloses a seat track assembly, generally shown at 10, for use in an automotive vehicle. The seat track assembly 10 includes a pair of laterally spaced apart track mechanisms, generally indicated at 12. The track mechanisms 12 slidably interconnect a vehicle seat (not shown) to a floor 14 of the vehicle. The seat track assembly 10 provides selective fore and aft adjustment of the seat among a plurality of seating positions along the floor 14 of the vehicle.

Each track mechanism 12 includes a fixed track 16 and a movable track 18, defining an open space 20 therebetween. The fixed track 16 is adapted to be mounted to the vehicle floor 14. The movable track 18 is fixedly secured to the seat and slidably coupled to the fixed track 16. The fixed 16 and movable 18 tracks define a longitudinal axis 22 along which the movable track 18 is adjustable relative to the fixed track 16. It will be appreciated that while only one of the track mechanisms 12 is shown and described in detail, both are substantially the same.

The seat track assembly 10 also includes a pair of latching mechanisms, generally shown at 24, for selectively locking the seat in any one of the plurality of seating positions. Referring to FIGS. 3 and 4, each latching mechanism 24 comprises a leaf spring 26 and a latch 28 and is disposed within the open space 20 between the fixed 16 and movable 18 tracks. The seat assembly 10 further includes a towel bar 30 operatively coupled to the pair of latching mechanisms 24 for actuating the latches 28 between a locked position, wherein the movable 18 and fixed 16 tracks are interlocked to prevent movement therebetween, as shown in FIG. 3, and an unlocked position, wherein the movable track 18 is slidably movable relative to the fixed track 16, as shown in FIG. 4.

Referring to FIGS. 2A through 2C, the towel bar 30 includes a pair of laterally spaced apart legs 32 each extending between a first end 34 and a second end 36. A handle 38 extends laterally between the first ends 34 of the legs 32, as shown in FIG. 1. Each leg 32 includes a crimped segment 40 having a reduced lateral thickness extending from the second end 36 to a point approximately midway between the first 34 and second 36 ends. The crimped segment 40 is disposed longitudinally within the open space 20 between the fixed 16 and movable 18 tracks. The second end 36 of each leg 32 includes a tapered edge 42 such that the second end 36 has a reduced vertical height.

Referring to FIGS. 3 and 4, the leaf spring 26 includes a generally arcuate segment 44 extending between a forward end 46 and a rearward end 48. The latch 28 is fixedly secured to the arcuate segment 44 approximately midway between the forward 46 and rearward 48 ends. The arcuate segment 44 biases the latch 28 into the locked position and permits resilient movement of the latch 28 along a vertical path between the locked and unlocked positions. A forward relief slot 50 extends longitudinally along the arcuate segment 44 between the latch 28 and the forward end 46. A rearward relief slot 52 extends longitudinally along the arcuate segment 44 between the latch 28 and the rearward end 48. A portion of the crimped segment 40 of the leg 32 of the towel bar 30 is disposed in the forward relief slot 50.

The forward end 46 of the leaf spring 26 includes a generally U-shaped segment 54. The U-shaped segment 54 is open along a bottom side 56 and a has a hole 58 in a top side 60. A rivet 62 or similar fastener extends through the hole 58 to fixedly secure the forward end 46 of the leaf spring 26 to an upper portion 64 of the movable track 18. The U-shaped segment 54 includes first 66 and second 68 slots for receiving the crimped segment 40 of the leg 32 of the towel bar 30 therethrough. A lower cross member 70 extends horizontally across the first slot 66 below the leg 32 and provides a downward pivot point for the towel bar 30. The lower cross member 70 engages a first indent or notch 72 in the leg 32 of the towel bar 30, as shown in FIGS. 2A through 2C. An upper cross member 74 extends horizontally across the second slot 68 above the leg 32 and provides an upward pivot point for the towel bar 30. The upper cross member 74 engages a second indent or notch 76 in the leg 32 of the towel bar 30, as shown in FIGS. 2A through 2C. The engagement between the lower cross member 70 and the first notch 72 and the upper cross member 74 and the second notch 76, securely retains the towel bar 30 to the latching mechanism 24 thereby preventing removal of the towel bar 30 by a seat occupant or during crash conditions.

The forward end 46 of the leaf spring 26 also includes a flexible, arcuate arm 78 extending forwardly from the bottom side 56 of the U-shaped segment 54. The arm 78 deflects downward when the handle 38 of the towel bar 30 is exposed to downward abuse loading, by being stepped on for example.

The rearward end 48 of the leaf spring 26 includes a vertical segment 80 for resisting bending of the arcuate segment 44 of the leaf spring 26. The vertical segment 80 extends upward to a horizontal tab 82 fixedly secured to the upper portion 64 of the movable track 18.

Referring to FIGS. 5 and 6, in the embodiment shown, the latch 28 includes a rectangular main body 84, a head 86, a neck 88 extending between the main body 84 and the head 86, and a latch plate 90. A longitudinally extending channel 92 is formed in the latch 28 for receiving the second end 36 of the leg 32 of the towel bar 30. The main body 84 is fixedly secured to the arcuate segment 44 of the leaf spring 26. The neck 88 extends through an opening 94 in the upper portion 64 of the movable track 16 such that the head 86 is disposed outside the track mechanism 12. The head 86 includes an engagement surface 96 extending laterally outward from the neck 88 to a distance beyond the opening 94 in the upper portion 64 of the movable track 16. The engagement surface 96 of the head 86 abuts the upper portion 64 of the movable track 16 when the latch 28 is in the unlocked position to limit downward vertical travel of the latch 28, as shown in FIGS. 2A, 4 and 6. The latch plate 90 extends laterally from the main body 84 of the latch 28 and in the embodiment shown includes three spaced apart windows or apertures 98. A plurality of teeth 100 is disposed along the fixed track 16. When the latch 28 is in the locked position, the apertures 98 engage or receive a portion of the plurality of teeth 100 therein, as shown in FIG. 5. When the latch 28 is in the unlocked position, the apertures 98 are disengaged or spaced from the plurality of teeth 100, as shown in FIG. 6.

In operation, starting with the towel bar 30 in a use position, as shown in FIG. 2B, the arcuate segment 44 of the leaf spring 26 biases the latch 28 upward into the locked position. In this position, the apertures 98 of the latch plate 90 are engaged with a portion of the plurality of teeth 100 disposed along the fixed track 16 such that the movable track 18 is interlocked with the fixed track 16, thereby preventing movement of the seat.

When the seat occupant desires to adjust the seat fore and aft as shown by arrow S, the handle 38 of the towel bar 30 is lifted upward as shown by arrow F1 in FIG. 2A. As the handle 38 is lifted, the leg 32 moves relative to the track mechanism 12 causing the leg 32 to pivot about the upper cross member 74 of the leaf spring 26, at the upward pivot point. The pivotal movement of the leg 32 about the upper cross member 74 causes the second end 36 to move downward. The downward movement of the second end 36 of the leg 32 urges the latch 28 downward against the bias of the arcuate segment 44 of the leaf spring 26 until the engagement surface 96 abuts the upper portion 64 of the movable track 18. The latch 28 is now in the unlocked position, shown in FIG. 2A. When the latch 28 is in the unlocked position, the apertures 98 of the latch plate 90 are disengaged from the plurality of teeth 100 disposed along the fixed track 16 such that the movable track 18 is slidably movable relative to the fixed track 16, thereby allowing selective fore and aft adjustment of the seat.

Once the seat is positioned, the handle 38 of the towel bar 30 is released. At the same time, the bias of the arcuate segment 44 of the leaf spring 26 urges the latch 28 upward to the locked position, shown in FIG. 2B. When the latch 28 is in the locked position, the apertures 98 of the latch plate 90 are engaged with a portion of the plurality of teeth 100 disposed along the fixed track 16 such that the movable track 18 is interlocked with the fixed track 16, thereby preventing further movement of the seat.

In certain instances, the handle 38 of the towel bar 30 is forced downward by abuse loading as shown by arrow F2 in FIG. 2C. As the handle 38 is forced downward, the leg 32 moves relative to the track mechanism 12 causing the leg 32 to pivot about the lower cross member 70 of the leaf spring 26, at the downward pivot point. The pivotal movement of the leg 32 about the lower cross member 70 causes the leg 32 to push against the arm 78, deflecting the arm 78 downwardly. At the same time, the second end 36 of the leg 32 moves upward relative to the latch 28, within the channel 92. Thus, the arm 78 allows downward movement of the towel bar 30 without causing damage to the leaf spring 26, latch 28, or the towel bar 30 itself.

The invention has been described here in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of words of description rather than limitation. Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically enumerated within the description. 

1. A seat track assembly for mounting a seat to a vehicle floor, said seat track assembly comprising: a track mechanism including a fixed track adapted to be mounted to the vehicle floor and a movable track adapted to be fixedly secured to the seat and slidably coupled to said fixed track; a latch operatively coupled to said movable track for selectively engaging said fixed track to interlock said movable track relative to said fixed track; a towel bar operatively coupled to said latch for actuating said latch between a locked position coupled with said fixed track to prevent sliding movement between said fixed and movable tracks and an unlocked position decoupled from said fixed track to allow sliding movement between said fixed and movable tracks; and a leaf spring extending between said movable track and said latch, said leaf spring biasing said latch into said locked position and permitting resilient movement of said latch along a linear path between said locked and unlocked positions in response to pivotal movement of said towel bar.
 2. A seat track assembly as set forth in claim 1 wherein said fixed and movable tracks define a longitudinally extending open space therebetween.
 3. A seat track assembly as set forth in claim 2 wherein said leaf spring and said latch are disposed within said open space between said fixed and movable tracks.
 4. A seat track assembly as set forth in claim 3 wherein said leaf spring includes an arcuate segment extending between forward and rearward ends adapted to be fixedly secured to said movable track, said arcuate segment biasing said latch into said locked position and permitting resilient movement of said latch along said linear path.
 5. A seat track assembly as set forth in claim 4 wherein said latch is fixedly secured to said arcuate segment of said leaf spring.
 6. A seat track assembly as set forth in claim 5 wherein said forward end of said leaf spring includes a generally U-shaped segment having an open bottom side and a top side fixedly secured to said movable track.
 7. A seat track assembly as set forth in claim 6 wherein said rearward end of said leaf spring includes a vertical segment fixedly secured to said movable track.
 8. A seat track assembly as set forth in claim 7 wherein said towel bar is pivotally coupled to said U-shaped segment of said leaf spring.
 9. A seat track assembly as set forth in claim 8 wherein said towel bar includes at least one leg extending between first and second ends and a handle disposed at said first end, said leg pivotally coupled to said U-shaped segment of said leaf spring between said first and second ends and operatively coupled to said latch at said second end for actuating said latch between said locked and unlocked positions.
 10. A seat track assembly as set forth in claim 9 wherein said forward end of said leaf spring includes a flexible arm below said leg of said towel bar allowing downward deflection of said leg in response to a downward load applied to said towel bar to prevent damage to at least one of said leaf spring, latch, and towel bar.
 11. A seat assembly as set forth in claim 10 wherein said flexible arm extends forwardly from said bottom side of said U-shaped segment of said leaf spring.
 12. A seat assembly as set forth in claim 11 wherein said latch includes a body fixedly secured to said arcuate segment of said leaf spring, a head disposed outside said track mechanism adjacent said movable track, a neck extending through an opening in said movable track and extending between said body and said head, a latch plate extending laterally from said body for selectively engaging a plurality of teeth disposed along said fixed track, and a longitudinally extending channel for receiving said second end of said leg of said towel bar.
 13. A seat assembly as set forth in claim 12 wherein said head includes an engagement surface extending beyond said opening in said movable track, said engagement surface abutting said movable track when said latch is in said unlocked position and spaced above said movable track when said latch is in said locked position.
 14. A seat track assembly as set forth in claim 13 wherein said latch plate includes a plurality of apertures, said plurality of apertures engaging said plurality of teeth when said latch is in said locked position and disengaged from said plurality of teeth when said latch is in said unlocked position. 